Home/ECAT/ECAT Chemistry Chemical Equilibrium Test Online

ECAT Chemistry Chemical Equilibrium Test Online

Maan AliLast Updated: April 19, 2025

Chemistry Chemical Equilibrium MCQS Online Test

ECAT Chemistry Chemical Equilibrium Chapter Online Test

Total Questions:	63
Time Allowed:	30 Minutes
Total Marks:	63
How to Attempt Test:	Please choose the right Option in MCQ-type question.
Test Helpful For:	ECAT Entry Test Chemistry Online Test Interview Questions about Chemisttry All Universities Entrance Test Recruitments Tests

ECAT Chemistry Chemical Equilibrium Test

Please wait...

Page 1 of 3

Chemistry

1. The rate at which a substance reacts is directly proportional to its active mass and the rate of reaction is directly proportional to the product of the active mass of reacting substances is known as

Le – Chatelier’s principle

None of all

Law of conservation of energy

Law of mass action

2. Who studied the effect of temperature on equilibrium?

Lewis

Vant Hoff

Van der Waal

Arrhenius

3. Which of the following is more acidic?

Bread

Bananas

Apples

Lemons

4. A buffer solution can be prepared by mixing

A strong acid and weak base

A strong acid and its salt

A weak base and its salt with strong acid

A weak acid and weak base

5. In reversible reactions, if the forward reaction occur very fast then reactant (s) is (are) __________

Unstable

At very high temperature

Solids

Stable

6. Two moles of HI was heated in a sealed tube at 440°C till the equilibrium was reached. HI was found to be 22% decomposed. The equilibrium constant for dissociation is

0.0796

0.282

0.0199

1.99

7. PH of human blood is

7.00

7.50

7.35

7.80

8. Units of Kc is

Kc may or may not have units

Moles² dm⁺⁶

Moles⁺² dm¯⁶

Moles¯² dm⁺⁶

9. When pressure is applied to the equilibrium system Ice ⇌ Water? Which of the following phenomenon will happen?

More ice will be formed

More water will be formed

Water will evaporate

Equilibrium will not be formed

10. At certain temperature, 50% of HI is dissociated into H₂ and I₂ the equilibrium constant is

0.25

1.0

0.5

3.0

11. Reaction which proceed in both the directions is called

Spontaneous

Irreversible

Reversible

Non spontaneous

12. In which of the following cases, the reaction goes farthest to completion?

K = 10⁰

K = 10

K = 10³

K = 10¯²

13. Which one of the following is a buffer solution?

Brine

Blood

Glue

Solution of CuSO4

14. If rate of concentration of reaction is equal to rate of concentration of products in reversible reaction the __________

Equilibrium will established

Reaction goes forward

Reaction goes backward

Reaction stops after some time

15. The relationship between Kp and Kc is give by

Kp = Kc (RT)-∆n

Kc = Kp (RT)∆n

Kp = Kc (RT)∆n

Kp = Kc (RT)∆

16. Kc > Products / Reactants favours

Equilibrium

Backward reaction

Reaction completed

Forward reaction

17. If a buffer solution of higher PH than seven is to be made we use

Weak base and its salt with a strong acid

Strong acid and strong base

Weak acid and its salt with a strong base

Weak acid and strong base

18. Which of the following factors will favour the reverse reaction in a chemical equilibrium?

Removal of one of the products regularly

Increase in concentration of one of the reactants

None of these

Increase in concentration of one of the products

19. The equilibrium will shift towards right by increasing ___________ of reactants

Temperature

Pressure

Impurity

Concentration

20. When rate of forward reaction is equal to rate of backward reaction, then the equilibrium established is called

Chemical equilibrium

None of all

Dynamic equilibrium

Static equilibrium

21. For the reaction 2A(g) + B(g) ⇌ 3C(g) + D(g) two moles each of A and B were taken into a flask. The following must always be true when the system attained equilibrium

[B] = [C]

[A] < [B]

[A] > [C]

[A] = [B]

22. When ever a week a base is dissolved in water, it gives its conjugate acid similarly a weal acid in water products its conjugate base. The conjugate acid base pair is stated by

Lowery Bronsted concept

Law of mass action

Common on effect

Le – Chatelier’s principle

23. The equilibrium constant in a reversible chemical reaction at a given temperature

Depends on the concentration of one of the products at equilibrium

Does not depend on the initial concentrations of reactants

Depends on the initial concentration of the reactants

Is not characteristic of the reaction

24. Temperature for preparation of SO₃ is

200 °C

400 °C

600 °C

400 – 500 °C

25. A basic Buffer solution can be prepared by mixing

Strong acid and its slat wit weak base

Strong base and its salt with weak acid

Weak acid and its slat with strong base

Weak base and its salt with strong acid

Page 2 of 3

26. Which pH is considered as basic?

27. In reversible reaction the changes in forward and backward reaction occur _________

None

Both a and b

Simultaneously

Individually

28. For equilibrium 2NO₂(g) ⇌ N₂O₄(g) + 14.6 kcal increase of temperature would

Favour the formation of N₂O₄

Stop the reaction

Not alter the equilibrium

Favour the decomposition of N₂O₄

29. Addition of CH3COOH and CH3COONa gives in water

Buffer solution

Acidic buffer solution

Standard solution

Both b and c

30. Which of the following gives a basic buffer?

NaCl + CH₃ COOH

NH₄OH + NH₄Cl

NaOH + CH₃ COONa

NaOH + NaCl

31. The reaction 2SO₂ + 2O₂ ⇌ 2SO will be favoured by

High temperature and low pressure

High temperature and high pressure

Low temperature and low pressure

Low temperature and high pressure

32. If the value of kc is very low then the forward reaction will occur __________

Randomly

Slowly

Moderately

Fast

33. The product of [0H¯][H⁺] at 25C° is

10¯²⁰

10¯¹⁰

10¹⁰

10¯¹⁴

34. The factor which changes equilibrium constant o the reaction A₂(g) + B₂(g) → 2 AB(g) is

Amounts of A₂ and B₂

Temperature

Catalyst

Total pressure

35. When sparingly soluble salt is in equilibrium with molar concentration of its oppositely charged ion when the product is called

Dissociation constant for an acid

Common ion effect

Solubility product

Dissociation constant

36. In a reversible chemical reaction having two reactants in equilibrium, if the concentration of the reactants are doubled then the equilibrium constant will

Remains the same

Also be doubled

Be halved

Becomes one fourth

37. Conjugate base of a very weak acid is

Strong base

Salt

Do not ionize

Weak base

38. By the addition of base in water pH will be

More than 7

No effect

Equal to 7

Less than 7

39. Preparation of buffer solution can be done by mixing

Strong base and its salt with weak acid

Weak acid and its salt with weak base

Weak base and its salt with strong acid

Strong acid and its salt with weak base

40. Which set of solutes will form a buffer when dissolved in water to make 1 litter of solution?

0.4 mole of CH3COOH with 0.4 mole of NaOH

0.4 mole of NH3 with 0.2 mole of HCl

0.0002M HCl

0.2 mole of NaCl with 0.2 mole of HNO3

41. Which of the following aqeous solution will be basic?

Na₂CO₃

NaCl

Fecl₃₋

Na₂SO₄

42. Synthesis of ammonia by Habor process is an example of ___________

Irreversible Reaction

Constant Reaction

Reversible Reaction

Decomposition Reaction

43. When H₂ and I₂ are mixed and equilibrium is attained, then

HI dissociation stops

Amount of HI formed is equal to the amount of H₂ dissociated

The reaction stops completely

None of these

44. Chemical equilibrium is referred to as dynamic because, at equilibrium, the

Equilibrium constant changes

Reactants and products keep reacting

Rates of the forward and backward reactions change

Concentrations of the reactants and products continue to change

45. Idea of PH and POH was put forward by

Einstein

Gibbs

Chadwiick

Sorenson

46. Which statements are correct for a reaction at equilibrium?
(I) The forward and reverse reactions both continue
(II) The rates of the forward and reverse reactions are equal
(III) The concentrations of reactants and products are equal

I and III only

I and II only

I, II and III only

II and III only

47. An equilibrium constant of 10¯⁴ for a reaction means that the reaction is

One that will have 50% product and 50% reactant at equilibrium

The equilibrium constant only relates to the speed of a reaction and not to the amount of product formed

One that is very favorable and will have mostly product at equilibrium

One that is unfavourable and will not have very much product at equilibrium

48. At start of reaction, concentration of reactants are on

Higher side

Lower side

Constant

Optimum side

49. Solubility of any salt can be determined from

Ksp

50. In a chemical reaction N₂ + 3H₂ ⇌ 2NH₃ at equilibrium point

Equal masses of N₂ and H₂ are reacting

The reaction has stopped

The same amount of ammonia is formed as is decomposed into N₂ and H₂

Equal volumes of N₂ and H₂ are reacting

Page 3 of 3

51. In an exothermic reversible reaction increase in temp shifts the equilibrium to

Reactant side

Remains unchanged

Fluctuate

Product side

52. AgCl dissolved with cone (2 x 10¯²) Ksp will be

4 x 10¯⁴

7.2 x 10¯⁶

3.6 x 10¯⁵

3.6 x 10¯⁶

53. A chemical reaction A ⇌ B is said to be in equilibrium when

Only 10% conversion of A to B has taken place

Complete conversion of A to B has taken place

Conversion of A to B is only 50% complete

The rate of transformation of A to B is just equal to rate of transformation of B to A in the system.

54. When pressure is applied to the given equilibrium ice water which of the following will happen

More water will be formed

Equilibrium will not be disturbed

More ice will be formed

Water will formed

55. The state of equilibrium refers to

Stationary state

Dynamic state

State or rest

State of inertness

56. What is the relationship between kp and kc?

kp = kc (RT)-∆n

Kc - kp (RT)∆n

kp = kc (RT)∆n

kc = kp (P)-∆n

57. What can affect the magnitude of equilibrium constant Kp of a reversible gaseous reaction

Pressure

None of these

Catalyst

Temperature

58. Le-Chatelier’s principle is sometime known as

Law of active mass

All of these

Law of mass action

Law of mobile equilibrium

59. For a reaction H₂ + I₂ ⇌ 2HI at 721 K, the value of equilibrium constant is 50. If 0.5 moles each of H₂ and I₂ is added to the system the value of equilibrium constant will be

0.2

0.02

60. pH of milk is

6.5

7.5

61. Water and ice are in equilibrium at 0C° and pressure is applied at this stage, then

More water is formed

Water evaporates

More ice is formed

Equilibrium is not disturbed

62. In an exothermic reaction, a 10° rise in temperature will

Produce some increase in Kc

Decrease the value of equilibrium constant

Double the value of Kc

Not produce any change in Kc

63. The rate of chemical reaction is directly proportional to the active mass of reactant this statement is known as ___________

Law of Equilibrium

Law of reaction

Law of Mass Action

None of these

You Can Learn and Gain more Knowledge through our Online Quiz and Testing system Just Search your desired Preparation subject at Gotest.

UET Peshawar Entry Test 2025 Registration Online ETEA Test D...
ECAT Statistics Test Set 17
ECAT Statistics Test Set 16
ECAT Statistics Test Set 15
ECAT Statistics Test Set 14
ECAT Statistics Test Set 13
ECAT Statistics Test Set 12
ECAT Statistics Test Set 11
ECAT Statistics Test Set 10
ECAT Statistics Test Set 9

Maan AliLast Updated: April 19, 2025

Facebook Twitter Reddit WhatsApp Share via Email Print

ECAT Chemistry Chemical Equilibrium Test Online

Chemistry Chemical Equilibrium MCQS Online Test

ECAT Chemistry Chemical Equilibrium Chapter Online Test

ECAT Chemistry Chemical Equilibrium Test

Chemistry

You Might Also Like

Maan Ali

One Comment

Leave a Reply Cancel reply

Chemistry Chemical Equilibrium MCQS Online Test

ECAT Chemistry Chemical Equilibrium Chapter Online Test

ECAT Chemistry Chemical Equilibrium Test

Chemistry

You Might Also Like

Maan Ali

Your Related

ECAT Mathematics Trigonometric Identities Online Test

UET Lahore Combined Entry Test 2025 ECAT Schedule and Registration

ECAT Mathematics Functions and Limits Online Test

ECAT English Antonyms 3 Online Test

ECAT Mathematics Introduction to Analytic Geometry Online Test

ECAT Physics Circular Motion Online Test

One Comment

Leave a Reply Cancel reply